Wheelchair seat back mount assembly and wheelchair therewith

ABSTRACT

An assembly for mounting a seat back shell to a wheelchair seat back cane comprises a first portion attachable to the seat back cane and a second portion attachable to the seat back shell. The portions mate to form a point of attachment by aligning one of the portions with the other portion and displacing one of the portions in relation to the other portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.60/878,293, filed Jan. 3, 2007, the disclosure of which is incorporatedherein by reference.

BACKGROUND OF THE INVENTION

This invention relates in general to wheelchairs and more particularlyto wheelchair seat back mount assemblies.

SUMMARY OF THE INVENTION

This invention relates to an assembly for mounting a seat back shell toa seat back cane of a wheelchair. The assembly comprises a first portionattachable to the seat back cane and a second portion attachable to theseat back shell. The portions mate to form a point of attachment byaligning one of the portions with the other portion and displacing oneof the portions in relation to the other portion.

Various aspects of this invention will become apparent to those skilledin the art from the following detailed description of the preferredembodiment, when read in light of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially exploded, environmental perspective view of a seatback mount assembly.

FIG. 2 is an enlarged-scale, exploded perspective view of the assemblyshown in FIG. 1.

FIG. 3 is an enlarged-scale, exploded perspective view of an adjustableclamp of the assembly shown in FIG. 1.

FIG. 4 is a reduced-scale, environmental partial rear perspective viewof the assembly shown in FIG. 1.

FIGS. 5A-5B are perspective views of a seat back being located andinstalled with the seat back mount assembly as shown in FIG. 1.

FIGS. 6A-6F are enlarged, elevational views of a mounting block and ac-shaped mounting bracket of the assembly shown in FIG. 1 at variousstages of cooperation.

FIG. 7 is a cross-sectional view of the mounting block and the c-shapedmounting bracket taken along the lines 7-7 in FIG. 6F.

FIG. 8 is an enlarged-scale, exploded perspective view of a bottom hookfor use with the assembly shown in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings, there is illustrated in FIG. 1 apartially exploded, environmental perspective view of a wheelchair seatback mount assembly 10. The assembly 10 may be comprised of twoportions, a first portion, generally indicated at 12, that may beattachable in relation to the wheelchair seat back canes 14 and a secondportion, generally indicated at 16, that may be attachable in relationto the wheelchair seat back shell 18. These two portions 12, 16 may mateto form an easy-to-use assembly.

In the exemplary embodiment shown in FIG. 2, the first portion 12 mayinclude a clamp bracket having a first part, which may be in the form ofa tube clamp plate 20, and a second part, which may be in the form of atube clamp hinge 22 a that may cooperate with the tube clamp plate 20.The tube clamp plate 20 may have a relatively planar main body portion20 a and a curved or hooked portion, generally indicated at 20 b,extending from the main body portion 20 a. Spaced fingers 20 c mayextend from the hooked portion 20 b. Aligning holes 20 d in the fingers20 c may receive a dowel pin 24, which may fit tightly in the holes 20d. The tube clamp hinge 22 may have a curved or hooked portion 22 a,which may be similar to the hook portion 20 b of the tube clamp plate20. A tab 22 b may extend from the hooked portion 22 a. The tab 22 b maybe sized to fit between the fingers 20 c. A groove 22 c on the tabs mayengage the dowel pin 24 to form a connection between the tube clampplate 20 and the tube clamp hinge 22. The engaging groove 22 c and dowelpin 24, in effect, may form a hinge. Multiple grooves, such as the twogrooves 22 c shown, may be provided for selective engagement with thedowel pin 24 to adjust the size of the clamp bracket, as will becomeapparent in the description that follows. A tongue 22 d may extend fromthe hooked portion 22 a, opposite the tab 22 b. One or more bores 22 emay pass the tongue 22 d. One or more fasteners 26, such as the capscrews shown, may pass through the bores 22 e, which may be counterbores, in the tongue 22 d and may be threaded into aligning threadedholes 20 e in the main body portion 20 a of the clamp bracket to fastenthe tongue 22 d of the tube clamp hinge 22 to the main body portion 20 aof the tube clamp plate 20. The fasteners 26 may be threaded into nuts,such as the lock nuts shown, on the opposite side (i.e., the blind sidewhen viewing FIG. 2) of the main body portion 20 a. The nuts may berecessed in hexagonal holes in the main body portion 20 a so that thehexagonal holes prevent the nuts from turning.

In the exemplary embodiment, a mounting block 28 may be supported inrelation to the clamp bracket, such as in relation to the tube clampplate 20 or in relation to the main body portion 20 a of the tube clampplate 20. The mounting block 28 may be mounted with one or morefasteners 30, such as the cap screws shown. For example, one or morebores 20 g, which may be counter bores, may be provided through the mainbody portion 20 a and may align with holes 28 a, 28 b through themounting block 28. The fasteners 30 may pass through the bores 20 g inthe main body portion 20 a and further through aligning holes 28 a, 28 bin the mounting block 28. The fasteners 30 may then be threaded intonuts, such as the lock nuts shown, on the opposite side of the mountingblock 28. The nuts may be recessed in holes in the mounting block 28(i.e., the blind side when viewing FIG. 2). The holes may be dimensionedand configured to prevent the nuts from turning.

It should be noted that the main body portion 20 a may have a pluralityof bores 20 g, including three sets or pairs of bores. Each pair may bearranged to support the seat back shell 18 at a different angle. Forexample, the three pairs of bores may support the seat back shell 18 at0, 5, and 10 degrees (i.e., relative to vertical when viewing FIG. 1).The main body portion 20 a may be provided with indicia, as shown inFIG. 3, corresponding with each pair of bores to indicate the angulardisposition of the seat back shell 18 if a corresponding pair of boresis used.

It should further be noted that at least one of the holes 28 b throughthe exemplary mounting block 28 may be curved or arcuate in shape topermit the mounting block 28 to pivot when the fasteners 30 areloosened, such as along the line B-B shown in FIG. 4. In particular, themounting block 28 may have two holes 28 a, 28 b. Two fasteners 30 maypass through the two holes 28 a, 28 b. One fastener 30 passing throughone hole 28 a may function as a pivot. The other fastener 30 may passthrough the other hole 28 b, which may be curved or arcuate in shape. Inthis way, the mounting block 28 may be able to pivot on the one fastener30 as the mounting block 28 moves in relation to the other fastener 30due to the provision of the curved or arcuate shaped hole 28 b.

As shown in FIG. 2, the exemplary mounting block 28 may have asubstantially circular shaped portion 28 c and a substantially oval orkidney shaped portion 28 d separated by a necked-down portion 28 e, whenviewed from a point parallel or along the axes A1, A2 of the holes 28 a,28 b therethrough. The hole 28 a for the fastener 30 that may functionas a pivot passes through the circular portion 28 c. The arcuate shapedhole 28 b may pass through the substantially oval or kidney shapedportion 28 d. Additionally, the mounting block 28 may have a first orouter portion 28 f and a second or inner portion 28 g, which may bereduced in size so as to be smaller in dimension when viewed from apoint transverse or crosswise from the axes A1, A2 of the holes 28 a, 28b therethrough. The larger outer portion 28 f may form a first flangethat extends radially outward in relation to the inner portion 28 g. Asubstantially pointed guide 28 h may extend (upwardly when viewing FIG.2) from the top of the flange.

The second portion 16 of the assembly 10 may include a substantiallyC-shaped mounting bracket having a first or outer portion 16 a and asecond or inner portion 16 b, which may be of a different size ordimension relative to the outer portion 16 a so that the inner portion16 b may form a second flange that may extend radially inward inrelation to the outer portion 16 a. The C-shaped mounting bracket maydefine a radial opening 16 d and the flange may define an axial opening16 e. The radial opening 16 d may permit passage of the mounting block28 when aligned or oriented in a first orientation and prevents passageof the mounting block 28 when displaced or oriented in a secondorientation. The axial opening 16 e may restrict axial passage of themounting block 28 when in the second orientation. The outer portion 16 amay be dimensioned and configured to be substantially complementary inshape to the outer portion 28 f of the mounting block 28, and mayinclude, for example, a region, such as the radial opening 16 d orchannel 16 d shown in FIG. 7, into which the pointed guide 28 h may beinserted. The inner portion 16 b may be dimensioned and configured to besubstantially complementary in shape to the outer portion 28 f of themounting block 28. The two flanges may cooperate to form an attachmentbetween the mounting block 28 and the C-shaped mounting bracket whenoriented in a certain orientation (e.g., the first orientation) inrelation to one another, as will become more apparent in the descriptionthat follows.

The exemplary C-shaped mounting bracket may be mounted in relation tothe seat back shell 18 by a top mount bracket 32. The exemplary topmount bracket 32 is a substantially L-shaped or V-shaped bracket havingone or more holes or slots 32 a therein that permit adjustment, such aslateral adjustment, of the top mount bracket 32 in relation to the seatback shell 18. The C-shaped mounting bracket may have one or more bores16 c, such as the counter bores shown, passing therethrough. The topmount bracket 32 may have threaded holes 32 b that may align with thebores 16 c. Fasteners 38, such as the cap screws shown, may pass throughthe bores 16 c and be threaded into the holes 32 b to fasten theC-shaped mounting bracket to the top mount bracket 32. The top mountbracket 32 may, in turn, be fastened to the seat back shell 18 in anysuitable manner, such as via the stud plate 40, washers 39, and nuts 41(e.g., locknuts) shown.

Referring back to FIG. 1, a mounting block 28 is shown fastened inrelation to each seat cane 14 and a C-shaped mounting bracket isfastened in relation to each side of the seat back shell 18. Anattachment may be formed between each mounting block 28 and acorresponding C-shaped mounting bracket. This may form two points ofattachment of the seat back shell 18 in relation to the seat back canes14. With the mounting block 28 and the C-shaped mounting bracketinstalled in relation to the seat back canes 14 and the seat back shell18, the seat back shell 18 may be easily installed by aligning thesecond portions 16 in relation to (e.g. over) the first portions 12 andthen rotating, or otherwise displacing, the seat back shell 18 downwardinto a positive latched position, as depicted in FIGS. 5A-5B.

With the provision of only two points of attachment, it may be simple toalign the mounting block 28 with the C-shaped mounting bracket. With themounting block 28 and the C-shaped mounting bracket aligned, themounting block 28 may be inserted into the C-shaped mounting bracketwith the pointed guide 28 h entering the channel 16 d of the C-shapedmounting bracket, as shown in FIGS. 6A-6B. The seat back shell (notshown) may then be rotated or pivoted (e.g., in a clockwise directionwhen viewing FIG. 6D) or otherwise displaced until the pointed guide 28h makes abutting contact with the C-shaped mounting bracket at the endof the channel 16 d and the substantially oval or kidney shaped portion28 d of the mounting block 28 makes abutting contact with acorresponding portion of the C-shaped mounting bracket, as shown inFIGS. 6E-6F. The abutting contact may resist further rotation or pivotalmovement of the seat back shell 18 (e.g., in a clockwise direction whenviewing FIG. 6D).

As shown in FIG. 7, the respective flanges of the mounting block 28 andthe C-shaped mounting bracket may cooperate to prevent lateral movementof the mounting block 28 and the C-shaped mounting bracket in relationto one another to form a point of attachment on each seat back cane 14.

To supplement the support provided by the two points of attachment, abottom hook 42, shown in FIG. 8, may be attached to each side of theseat back shell 18 at a lower portion of the seat back shell 18 (i.e.,below the attachment points). The exemplary bottom hooks 42 may beprovided with one or more holes or slots 42 a therein that permitlateral adjustment of the bottom hooks 42 in relation to the seat backshell 18. This may permit proper alignment of the bottom hooks 42 inrelation to the seat back canes 14. As shown in FIG. 1, the bottom hooks42 may abut the seat back canes 14 to limit movement of the lowerportion to the seat back shell 18 in relation to the canes 14. Thebottom hooks 42 may be fastened to the seat back shell 18 in anysuitable manner, such as with the stud plates 44, washers 46 and nuts 48shown. The nuts 48 may be lock nuts. A covering material 50, such as aplastic or rubber covering may cover the bottom hooks 42 to provide arelatively resilient contact between the bottom hooks 42 and the canes14.

It should be noted that different shaped back canes can be accommodatedby the pivotal adjustment of the mounting block 28 in relation to thetube clamp plate 20. This may further insure that the bottom hooks 42are properly aligned with the seat back canes 14. For example, differentback canes may be at different angles relative to vertical, or not maynot follow a straight line and thus have portions that are at differentangles relative to vertical. In these cases, the orientation of themounting block 28 may be pivotally adjusted in relation to the backcanes, depending on the angle of the back cane in relation to verticalat the point which the mounting block 28 is mounted to the back cane.

To accommodate different diameter canes 14, the clamp bracket may beadjustable. As described above, the clamp bracket may have a tube clampplate 20 with a pin 24 and a tube clamp hinge 22 with grooves 22 c thatmay be selectively engageable with the pin 24 so the clamp 22 may beused with different sized seat back canes 14. For example, one groovemay accommodate ⅞ inch (22 mm) diameter canes while another groove mayaccommodate 1 inch (25 mm) diameter canes.

Most of the load applied on the seat back shell 18 may be applied in theshoulder area of the shell 18. The main attachment points of theassembly 10 may be in the same area, providing good support andminimizing risk that the seat back shell 18 will become unintentionallydetached.

It should be appreciated that the clamp bracket and top mount bracketare exemplary brackets and other forms of connection may be provided forthe mounting block 28 and the C-shaped mounting bracket. It shouldfurther be appreciated that the mounting block 28 and the C-shapedmounting bracket are exemplary embodiments and that the mounting blockand the mounting bracket may take on other shapes or forms. Further, thefasteners 26, 30, 38 and stud plates 40, 44 are exemplary fasteners andother fasteners may be employed. The bottom hook 42 is described forexemplary purposes and other structure may be suitable for use in theplace of the bottom hooks 42.

It should be appreciated that the mounting block and mounting bracketmay be cooperatively configured in any suitable manner, whereby at leastone of either the mounting block or mounting bracket may be oriented insuch a way to cooperate with the other one of either the mounting blockor mounting bracket, such as by insertion, and then displaced, such asby rotation or other suitable displacement, to interlock the mountingblock and the mounting bracket. The axial opening is provided as anexample of a captive or restrictive opening, which may be defined by anannular flange or other suitable structure or configuration. Otherstructure may be suitable for interlock the mounting block and themounting bracket. Further, the pointed guide functions in cooperationwith the mounting bracket as an interference member. It should beappreciated that other structure may be suitable for functioning as aninterference member.

The principle and mode of operation of this invention have beenexplained and illustrated in its preferred embodiment. However, it mustbe understood that this invention may be practiced otherwise than asspecifically explained and illustrated without departing from its spiritor scope.

1. An assembly for mounting a seat back shell to a wheelchair seat backcane, the assembly comprising: a first portion attachable to the seatback cane, and a second portion attachable to the seat back shell, theportions mating to form a point of attachment by aligning one of theportions with the other portion and displacing one of the portions inrelation to the other portion.
 2. The assembly of claim 1 wherein theshell is attachable to two spaced apart seat back canes, thus formingtwo points of attachment.
 3. An assembly for mounting a seat back shellto a wheelchair seat back cane, the assembly comprising: a first portionattachable in relation to the seat back cane; and a second portionattachable in relation to the seat back shell, the second portion beingconfigured to receive the first portion and rotate in relation to thefirst portion to lock the second portion in relation to the firstportion.
 4. The assembly of claim 3 wherein the first portion comprisesa tube clamp that is attachable in relation to the seat back cane. 5.The assembly of claim 4 wherein the tube clamp comprises a first partand a second part hinged in relation to the first part.
 6. The assemblyof claim 5 wherein the second part is hinged in relation to the firstpart in a plurality of positions to accommodate different size seat backcanes.
 7. The assembly of claim 4 wherein the first portion furthercomprises a mounting block attachable in relation to the tube clamp, thesecond portion being configured to receive the mounting block and rotatein relation to the mounting block to lock the second portion in relationto the first portion.
 8. The assembly of claim 7 wherein the mountingblock is attachable in relation to the tube clamp in a plurality ofpositions to adjust the angle of the seat back shell in relation to theseat back canes.
 9. The assembly of claim 7 wherein the mounting blockis pivotally adjustable in relation to the tube clamp in any one of theplurality of positions to accommodate different shaped back canes. 10.The assembly of claim 3 wherein the second portion comprises a mountingbracket that is attachable in relation to the seat back shell.
 11. Theassembly of claim 10 wherein the mounting bracket is adjustable inrelation to the seat back shell.
 12. The assembly of claim 10 whereinthe mounting bracket is laterally adjustable in relation to the seatback shell.
 13. The assembly of claim 3 wherein the first portioncomprises a mounting block and the second portion comprises a mountingbracket, the mounting bracket comprising a radial opening and an axialopening, the radial opening permitting passage of the mounting blockwhen oriented in a first orientation and preventing passage of themounting block when oriented in a second orientation, the axial openingrestricting axial passage of the mounting block.
 14. The assembly ofclaim 13 wherein the mounting block comprises an inner portion and anouter portion, the inner portion comprising a substantially circularshaped portion and a kidney shaped portion with a necked-down portiontherebetween, the outer portion defining a first flange, and wherein themounting bracket is substantially C-shaped and comprises an innerportion defining a second flange, the axial opening being bound by thesecond flange and having a shape complementary to the mounting blockinner portion, the first and second flanges being dimensioned andconfigured to restrict axial passage of the mounting block inner portionthrough the mounting bracket.
 15. An assembly for mounting a seat backshell to spaced apart wheelchair seat back canes, the assemblycomprising: a pair of first portions, the first portions beingattachable in relation to the seat back canes; and a pair of secondportions, the second portions being attachable in relation to opposingsides of the seat back shell, the second portions being configured toreceive the first portions and rotate in relation to the first portionsto lock the second portions in relation to the first portions and thusform a two-point mounting assembly.
 16. The assembly of claim 15 whereinthe first portions each comprises a tube clamp attachable in relation tothe seat back canes, the tube clamp comprising a first part and a secondpart hinged in relation to the first part in a plurality of positions toaccommodate different size seat back canes.
 17. The assembly of claim 16wherein the first portions each comprises a mounting block attachable inrelation to the tube clamp, the second portions being configured toreceive the mounting blocks and rotate in relation to the mountingblocks to lock the second portions in relation to the first portions.18. The assembly of claim 17 wherein the mounting blocks are attachablein relation to the tube clamps in a plurality of positions to adjust theangle of the seat back shell in relation to the seat back canes.
 19. Theassembly of claim 15 wherein the second portions each comprise amounting bracket that is attachable in relation to the seat back shell,the mounting bracket being laterally adjustable in relation to the seatback shell.
 20. The assembly of claim 15 further comprising a pair ofhooks, the hooks each being attachable in relation to the seat backshell below the second portions.